1. Field of the Invention
This invention relates to a chemical analysis film supplier for supplying, in a biochemical analysis apparatus, chemical analysis films each having a reagent layer containing a reagent whose optical density changes through a chemical reaction, a biochemical reaction, an immunoreaction or the like with a specific biochemical component contained in a sample liquid such as blood or urine.
2. Description of the Prior Art
There has been put into practice a "dry-to-touch" chemical analysis film with which the content of a specific chemical component contained in a sample liquid, the activity thereof or the content of a solid component can be quantitatively analyzed by only spotting a droplet of the sample liquid on the film. As such a dry chemical analysis film, there has been known an integrated multi-layered chemical analysis film (sometimes referred to as "multi-layered chemical analysis element") comprising a support sheet of organic polymer and at least one reagent layer which contains a reagent and is formed on the support sheet. A spreading layer is sometimes provided over the reagent layer. Further a dry chemical analysis element which is formed of filter paper and has one or more layers has been proposed and partly put into practice.
When quantitatively analyzing the chemical components or the like contained in a sample liquid using such a dry chemical analysis film, a droplet of the sample liquid is spotted on the film (on the spreading layer when the film is provided with a spreading layer and on the reagent layer when the film is not provided with a spreading layer) and is held at a constant temperature for a predetermined time (incubation) in an incubator so that coloring reaction occurs, and the optical density of the color formed by the coloring reaction is optically measured. That is, measuring light containing a wavelength which is pre-selected according to the combination of the component to be analyzed and the reagent contained in the reagent layer of the film is projected onto the film and the optical density of the film is measured. Then the concentration or the activity of the component to be analyzed is determined on the basis of the optical density using a calibration curve which represents the relation between the concentration of the biochemical component and the optical density.
The integrated multi-layered chemical analysis film is generally in the form of a film chip of a predetermined shape such as square or rectangle. The film chip is sometimes provided with a frame of organic polymer for facilitating automated handling of the chemical analysis film and is used in the form of a chemical analysis slide. In a biochemical analysis apparatus we have proposed previously, the film chip is used at it is without frame (will be referred to as "frameless chemical analysis film", hereinbelow). A plurality of the frameless chemical analysis films are loaded in a cartridge and the cartridge is loaded in a chemical analysis film supplier for a biochemical analysis apparatus. The frameless chemical analysis films are taken out from the cartridge in the supplier one by one.
In the biochemical analysis apparatus, a plurality of cartridges containing therein different chemical analysis films are loaded in a chemical analysis film supplier and the chemical analysis films are taken out one by one from a cartridge selected according to the item of measurement. For example, in the chemical analysis film supplier disclosed in Japanese Unexamined Patent Publication 59(1984)-20858, U.S. Pat. No. 4,512,952, U.S. Pat. No. 5,089,418 or the like, the cartridges are arranged in a circle on a rotary support in the chemical analysis film supplier and the support is rotated to bring a selected cartridge to a film take-out mechanism, which is arranged to push out a chemical analysis film from the cartridge by a sliding member which slides from the inside out.
In order to maintain the performance of the dry chemical analysis films to ensure accuracy of measurement, the films should be stored in the chemical analysis film supplier at a humidity in a predetermined range. That is, the chemical analysis film contains biochemical materials such as enzymes, antibodies and the like selected according to the item of the measurement and generally it is preferred that the chemical analysis films be stored at a low humidity so that initiation of reaction is suppressed. Some chemical analysis films, e.g., those for determining total protein (TP), high density lipoprotein-cholesterol (HDL-C), albumin (ALB) or the like, should be stored under a different humidity condition, i.e., in a range somewhat above 0% RH.
As disclosed in Japanese Unexamined Utility Model Publication No. 5(1993)-33048 (U.S. Pat. No. 5,043,143), there has been proposed a technique in which a first chamber containing therein a moistening means such as a sponge member soaked with water and a second chamber containing therein a dehumidifying means such as a drying agent are provided to communicate with the bottom of a film storage chamber in which the chemical analysis films are stored, and the humidity in the film storage chamber is controlled by causing the film storage chamber to communicate selectively with the first or second chamber.
However, the chemical analysis film supplier in accordance with the technique is disadvantageous in that since the driving mechanism for taking out the dry chemical analysis films from the cartridges arranged in a circle is disposed at the center of the chemical analysis film supplier, the space for accommodating a moisture-absorptive agent (dehydrating agent or humidity conditioning agent) for keeping the chemical analysis films under a predetermined humidity condition must be disposed below or outside the film storage chamber, which makes it troublesome to change the moisture-absorptive agent, makes it difficult to reduce the size of the chemical analysis film supplier and adds to the cost.
Especially when a plurality of cartridges are to be stored under different humidity conditions, the space for storing the cartridges must be partitioned into a plurality of film storage chambers and a moisture-absorptive agent (dehydrating agent or moisture conditioning agent) must be provided for each of the film storage chambers, which further complicates the structure in the chemical analysis film supplier and makes it further troublesome to change the moisture-absorptive agent.
Further the conventional chemical analysis film supplier generally comprises a container which can keep the atmosphere therein at a low humidity and a cartridge holding member which is provided with a plurality of cartridge holding portions and is supported in the container so that the cartridge holding member is movable relative to the container to bring the cartridge held in each of cartridge holding portions to a film takeout port formed in the container. The cartridges are put in the container body through a cartridge inlet-outlet port formed in the container. This arrangement gives rise to the following problem.
That is, sometimes it is necessary to transfer all the cartridges in the chemical analysis film supplier to another place held at a low temperature and a low humidity such as in a refrigerator, for instance, when the chemical analysis film supplier fails or is to be maintained, or when the chemical analysis film stored therein is not to be used for a predetermined time interval. When the cartridges are unloaded from the chemical analysis film supplier, all the cartridges in the supplier must be taken out one by one through the cartridge inlet-outlet port and when the cartridges are reloaded in the chemical analysis film supplier, the cartridges must be inserted into the supplier one by one through the cartridge inlet-outlet port. This is a very troublesome work. Further, it is preferred that each cartridge unloaded from the supplier be returned to the same cartridge holding portion. For this purpose, the cartridges must be unloaded and reloaded while checking the relation between the cartridges and the cartridge holding portions. This operation is not only very troublesome but also apt to lead an error in positioning the cartridges.
The problem described above is true of a chemical analysis film supplier where the chemical analysis films are directly loaded in film holding portions of a film holding member in the supplier without use of cartridge.